1. Field of the Invention
The present invention relates in general to graphical user interfaces for data processing systems, and in particular to an improved scrolling function for graphical user interfaces.
2. Description of the Prior Art
Modern data processing systems allow operators to manipulate data at astounding rates; processing speeds of microprocessors in data processing systems have long ago ceased to be a major impediment to the speed and efficiency of most operator activities. Instead, cumbersome user interfaces have developed into a potentially serious impediment to efficient operator interaction with data processing systems. The operations of opening, positioning, sizing, and closing windows can place considerable strain on a user, particularly when complicated tasks are being performed or when the computer display screen is crowded with overlapping windows or work areas.
One other significant impediment to efficient use of data processing systems is that the windows or work spaces provided in most graphical user interfaces are relatively small in comparison to the software objects that are displayed therein. For example, most documents cannot be contained within a single work space. Likewise, most graphical or image files cannot be displayed in the work space of a graphical user interface. Accordingly, scrolling is frequently required in order to view all parts of the software object. Most graphical user interfaces for data processing systems include scroll bars which allow for vertical and horizontal scrolling, which effectively moves the software object upward or downward and leftward or rightward through the work space, and which provides an illusion of scrolling. Typically, scrolling is accomplished by utilizing a graphical pointing device to engage the vertical or horizontal scroll bar icon. Typically, the vertical scroll bar icon is located adjacent the work space, and includes a scroll bar track and a scroll bar slider member which is movable relative to the scroll bar track. The horizontal scroll bar is typically located at the bottom of the work space and likewise includes a scroll bar track and a scroll bar slider member which is movable relative to the scroll bar track. Typically, to initiate scrolling, the graphical pointing device must be located on the scroll bar icon, and the left mouse button must be depressed in a clicking operation which allows for a drag-and-drop manipulation of the scroll bar slider member relative to the scroll bar track or conventional dedicated "buttons" for scrolling movement must be activated. In some prior art graphical user inter-faces, the graphical pointing device may be removed from the scroll bar track, without interrupting the scroll bar functionality. In other words, the graphical pointing device may be moved away from the vertical or horizontal scroll bar track, and placed in the work space. In this position, clicking the mouse and moving the graphical pointing device upward within the work space causes upward scrolling, moving the mouse downward within the work space causes downward scrolling, moving the mouse leftward within the work space causes leftward scrolling, and moving the mouse rightward within the work space causes rightward scrolling.
One impediment with the prior art approach is that it is relatively easy for the operator to become disoriented or confused about his/her location within the software object when the graphical pointing device is located within the work space and utilized for scrolling operations.